diff --git a/compiler/iface/IfaceSyn.lhs b/compiler/iface/IfaceSyn.lhs
index 7484b3710f65fbc0ff5da1b50667796fd0446b0b..1283b095fdccf3d79b44b29b8bd5c68caec5fc88 100644
--- a/compiler/iface/IfaceSyn.lhs
+++ b/compiler/iface/IfaceSyn.lhs
@@ -1047,7 +1047,7 @@ instance Outputable IfaceDecl where
 pprIfaceDecl :: IfaceDecl -> SDoc
 pprIfaceDecl (IfaceId {ifName = var, ifType = ty,
                        ifIdDetails = details, ifIdInfo = info})
-  = sep [ ppr var <+> dcolon <+> ppr ty,
+  = sep [ pprPrefixOcc var <+> dcolon <+> ppr ty,
           nest 2 (ppr details),
           nest 2 (ppr info) ]